This invention relates to x-ray positioning systems; and, more particularly, to a dual laser apparatus and method for aiming at and targeting the center of an x-ray field for subsequent use in performing medical diagnostics or procedures involving the use of an x-ray machine.
In setting up for a procedure involving x-rays, it is important to properly align the equipment so that when x-rays are directed at a patient's or subject's body by an x-ray machine, they are directed at the correct part of a person's anatomy. This prevents potentially harmful radiation for being directed at wrong parts of the person's body, or inadvertently at others who may be present for the procedure. There are a number of currently known procedures for affecting proper alignment, and while each may work to accomplish their goal, each has certain drawbacks.
In U.S. Pat. No. 6,267,502 to McNeirney, there is disclosed a device to assist alignment of an x-ray beam center to an image receptor center; after which the device is removed so the patient can be properly put in place for an x-ray procedure which is to be performed. The drawback with McNeirney is that the device must be removed before the patient is in place, and because of this, real-time information as to the location of the x-ray field's center cannot be known during the procedure and harm could result if the center shifts for some reason. In addition, McNierney also requires use of an opaque target which has to be positioned in the radiation field as part of the alignment process.
Next, U.S. Pat. No. 7,806,591 to Wang is directed to determining the positional alignment between a light beam and an x-ray beam, and vice versa. The device is for use on a non C-arm type fluoroscopy unit and employs two laser lights attached to an x-ray source. The lights are aimed at a reflective surface which is attached to, and located to one side of an image receptor. The receptor reflects the laser light back to the x-ray source with an operator then observing where light strikes the x-ray source so to determine if it is centered, or make appropriate adjustments to center it.
Among the drawbacks with the Wang device is that, during a procedure, the reflector is positioned below and to the side of the patient being x-rayed. If the patient is large, the reflector may be blocked from receiving the projected laser light. Further, the proximity of the reflector to the patient and x-ray technician is such that it can easily be dislodged or misaligned by the patient or technician. Also, use of the Wang device involves a significant amount of training before a technician can reliably set it up and use it. This includes having the technician constantly having to monitor two areas, the laser reflector, and the x-ray source.
U.S. Pat. No. 8,434,942 to Lenchig is directed at lighting apparatus for flooding light onto an area within an x-ray field of a non-portable C-arm fluoroscopy unit so to project a bright light into the area. The apparatus comprises a housing that surrounds an image receptor of an x-ray fluoroscope, and at least one light-emitting element installed within the housing and aimed downwards towards an x-ray source of the fluoroscope. The apparatus further employs up to three focusing mechanisms for focusing the light emitted. These fit over the light-emitting element, and a fastener for coupling the housing to an x-ray receiving element. A separate power supply unit, not coupled to the housing, provides electrical current to the light-emitting element.
Drawbacks of the apparatus are that it is designed for flooding light into a general area, not targeting a point; the large number of components an operator must install with respect to the optical elements; that the apparatus takes up space in the area below an image receptor, which area is for patient placement; that power to run the apparatus is routed through an electrical cord from a remote source; and, its non-portability.
U.S. Pat. No. 8,755,114 to Tanner describes a device for use with a binocular microscope for light illumination and uses a targeting light directed at a subject area. The device includes a control unit and a light source coupled with a targeting laser light to position a specimen in the microscope's field of view for examining the specimen. The device is ring-shaped and attached to the microscope using set screws. It is located below the magnifying objective lens and above the subject stage. Power to the device is by an electrical power cord connected between an external power source and the control unit. The control unit, which is located some distance from the ring shaped device, enables an operator to control light intensity. Connecting the components of the device and the control unit together, and their subsequent disengagement, is a time consuming process.
Other drawbacks of the device are that power is required from a remote source and a power cord is not supplied with the device; special tools are required for the device's assembly; the device is only for use with a microscope; when installed, the device attaches below the face of the microscope and invades the space designated for subject placement; the device requires multiple parts (e.g., control unit and power supply) not incorporated into a single unit; the device requires placement of a beam-splitter or mirror into the optical path of the microscope; the lasers used cannot be adjusted; and, the microscope does not involve radiation.
The current invention, as described hereinafter, overcomes the various drawbacks associated with this art, and has other advantages as well.